I first saw Koo Hye Sun in Pure in Heart playing Yang Gukhwa. I believe she made it one of the best Korean dramas I've seen on US television. I became an instant fan, Because of the enjoyment I got by watching her work, and by the disappointment of US tv not showing more of her work, I bought the dramas Boys Over Flowers and The King and I. She's truly fantastic in those, also.
I wish that someday she'd come to the US and visit her fans here.